1. Field of the Invention
The present invention relates to an improved assembly of a carriage and a guiding rail for a curtain, which carriage includes a plurality of vertical and horizontal limiting rollers, the topmost of the vertical limiting rollers being located to contact the bottom of the guiding rail, while the horizontal limiting rollers are provided at both ends and inside of the carriage, so that the vertical and the horizontal components of the force exerted for pulling the curtain can only make the limiting rollers rotate, and thus prevents the guiding rail from distortion, and prolongs the useful life of the guiding rail.
2. Description of the Prior Art
A manually operated curtain A (referring to FIG. 6) is pulled directly to stretch or contract it without using ropes, and a user always catches the front end of the curtain A by hand, or uses a stick, for pulling a carriage B, will the pulling force being a down-ward as well as sideward force relative to the carriage B above the curtain A. To divide the force into vertical and horizontal components, we can find that the force may be a leftward or rightward biasing force and a downward biasing force relative to the carriage B. A conventional carriage for a curtain (FIG. 7) has a pair of rollers 2 on each end of the main body 1 of the sheet carriage, with the rollers 2 being located on both bottom lateral rails 31 of the guiding rail 3 to support the weight of the curtain A and for sliding of the carriage. The bottom lateral rails 31 are folded upwardly to form a pair of inner edges 32, so that the main body 1 is just interposed between the bottom side rails 31 of the guiding rail 3. However, when the curtain is in operation, sideward and forward pulling force render the front and the rear ends of the main body 1 of the carriage to bias leftwardly or rightwardly about a vertical axis (as shown in FIG. 7-1), and render the upper and the lower ends thereof to bias leftwardly or rightwardly about a horizontal axis (as shown in FIG. 7-2), so that in operation of the carriage B, the main body 1 always biases to create sliding friction with the inner edges 32 of the rail 3. The rollers 2 hence are unevenly loaded, and are thereby subjected to damage, breaking, and render it difficult for the user to pull the curtain.